1. Field of the Invention
The present invention relates to a printing and drying machine and, more particularly, to a workpiece carrier positioning structure for use in an auto printing and drying machine to position the workpiece carrier of each carriage accurately in position for enabling the carried workpiece to be printed or dried by the corresponding printing module or drying module.
2. Description of the Related Art
Conventionally, auto-rotary printers are used for printing T-shirts and various cut-pieces. An auto-rotary printer for this purpose comprises a driving mechanism at the center, and a plurality of printing modules respectively located on the radial rod (members of the driving mechanism. A circular conveyer system is provided below the printing modules, carrying a plurality of workpiece carriers. The circular conveyer system is rotated intermittently. Upon each stroke of the motion of the circular conveyer system, the driving mechanism is operated to lower the printing modules, thereby causing the printing modules to print the desired printing on the T-shirt or cut-piece on each workpiece carrier. The printed T-shirts or cut-pieces are further delivered through a drying unit and then well dried. This design of auto-rotary printer is not extendable, i.e., the number of the printing modules cannot be reduced or increased subject to the desired capacity. Further, this design of auto-rotary printer requires much installation space.
In order to eliminate the aforesaid drawbacks, the present invention invented an extendable auto printing and drying machine that can be extended subject to the desired capacity. This design of extendable auto printing and drying machine is functional. However, it still has a small drawback. When printing or drying the T-shirt or cut-piece on the corresponding workpiece carrier, the workpiece carrier tends to be vibrated by the corresponding printing module or drying module, affecting the performance of the printing or drying action.
The present invention has been accomplished under the circumstances in view. It is main object of the present invention to provide a workpiece carrier positioning structure for use in an auto printing and drying machine, which accurately positively holds the workpiece carrier of the corresponding carriage in position for enabling the carried workpiece to be printed or dried by the corresponding printing module or drying module accurately. According to the present invention, the workpiece carrier is transversely slidably mounted on transverse axles at the carriage and supported between compression springs on the transverse axles, and a longitudinal slide is controlled by an air cylinder to move a notched stop block into engagement with a roller at the bottom side of the workpiece carrier to hold the workpiece carrier in the printing/drying position positively when the carriage approached.